Optical illumination system

ABSTRACT

Systems and methods are provided that combine an amplitude modulation SLM with a phase modulating SLM in the same optical illumination system. The combination of the amplitude modulation SLM and the phase modulation SLM allows the optical illumination to compensate for the limitations of amplitude modulation SLM by using phase modulating SLM and conversely to compensate for the limitations of phase modulation SLM by using amplitude modulating SLM.

RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 14/776,686 filed Sep. 14, 2015, which is a U.S. National Stageof International patent application no. PCT/US2014/028536 filed Mar. 14,2014, which claims the benefit of U.S. provisional patent applicationNo. 61/781,105, filed Mar. 14, 2013, each of which is incorporatedherein by reference in its entirety.

BACKGROUND Field of the Invention

The present disclosure generally relates to optical illumination systemsare more specifically relates to the use of amplitude modulation spatiallight modulators in combination with phase modulation spatial lightmodulators in an optical illumination system.

Related Art

One conventional means to create spatial light patterns is to modulatethe amplitude of light as a function of position within a twodimensional plane. Examples of such conventional means includetraditional film projection, liquid crystal display (“LCD”) projectors,and digital micromirror device (“DMD”) based projectors. DMD devices arereflective devices that can project very high intensities of light andcan be very rapidly switched. A fundamental limitation of DMD devices isthat they are extremely inefficient at utilizing the available lightenergy when only a small portion of the target area (e.g., a sample)needs to be illuminated. This is particularly problematic if smalllocalized regions of the sample require very high light intensities,such as during photolysis of caged compound and stimulation foroptogenetics. In addition, DMD devices embody a fundamentally twodimensional technology and cannot simultaneously control light in threedimensions.

An alternate conventional means to create spatial light patterns is tomodulate the phase of the light. An example of this conventional meansincludes holography. Fundamental limitations of digital holographicsystems include the production of zero and higher order diffractionpatterns as well as ghost images that must be blocked. Typically, astatic physical barrier is used to block the zero order diffractionpattern. Currently, there are no practical solutions to block the higherorder diffraction patterns and ghost images and in many circumstancesthese extraneous patterns are unacceptable. In addition, most phase onlyspatial light modulators (“SLMs”) are unable to rapidly switch betweendifferent patterns. Moreover, the diffraction efficiency and thereforethe distribution of light in the field of view of the objective lensdepend on the lateral position. In most applications for patternedillumination it is desirable to have a flat field in terms of intensityas a function of space.

Yet another alternate conventional means for creating spatial lightpatterns is to sequentially scan a series of points rapidly as iscurrently done with confocal laser scanning microscopy and two-photonmicroscopy. This means is problematic because the speed of scanning isinsufficient and is further problematic due to limitations related tohow much power any single spot on the sample can tolerate.

Therefore, what is needed are systems and methods that overcome thesesignificant problems found in the conventional systems as describedabove.

SUMMARY

The present disclosure described systems and methods that overcome thelimitations identified above by combining an amplitude modulation SLMwith a phase modulating SLM in the same optical illumination system. Thecombination of the amplitude modulation SLM and the phase modulation SLMallows the optical illumination to compensate for the limitations ofamplitude modulation SLM by using phase modulating SLM and conversely tocompensate for the limitations of phase modulation SLM by usingamplitude modulating SLM.

In one embodiment, an optical illumination system having an optical axisis provided where there optical illumination system includes an imageplane that is perpendicular to the optical axis and an aperture planethat is perpendicular to the optical axis. The system also includes anamplitude modulating spatial light modulator positioned in a conjugateplane of the image plane and configured to direct an optical signal tothe image plane. The system also includes a phase modulating spatiallight modulator positioned in a conjugate plane of the aperture planeand configured to direct an optical signal to the amplitude modulatingspatial light modulator. The system also includes a coherence lightsource optically coupled with the phase modulating spatial lightmodulator, wherein the coherence light source is configured toilluminate at least a portion of the image plane by directing an opticalsignal to the phase modulating spatial light modulator, which directssaid optical signal to the amplitude modulating spatial light modulator,which directs said optical signal to the image plane.

Other features and advantages of the present invention will become morereadily apparent to those of ordinary skill in the art after reviewingthe following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure and operation of the present invention will be understoodfrom a review of the following detailed description and the accompanyingdrawings in which like reference numerals refer to like parts and inwhich:

FIG. 1A illustrates an example optical illumination system according toan embodiment;

FIG. 1B is a simplified illustration of an optical path in the opticalillumination system of FIG. 1A;

FIG. 1C illustrates a plural optical path example of the opticalillumination system of FIG. 1A;

FIG. 2A is a simplified illustration of an alternative optical path inthe optical illumination system of FIG. 1A;

FIG. 2B illustrates an alternative plural optical path example of theoptical illumination system of FIG. 1A;

FIG. 3A is a simplified illustration of an alternative optical path inthe optical illumination system of FIG. 1A;

FIG. 3B illustrates an alternative plural optical path example of theoptical illumination system of FIG. 1A;

FIG. 4 illustrates a portion of an alternative example opticalillumination system according to an embodiment;

FIG. 5 is a flow diagram illustrating an example process forilluminating a sample in an optical illumination system according to anembodiment;

FIG. 6 is a block diagram illustrating an example wired or wirelessprocessor enabled device that may be used in connection with variousembodiments described herein.

DETAILED DESCRIPTION

Certain embodiments disclosed herein provide an optical illuminationsystem comprising a phase modulating spatial light modulator situated ata conjugate of the aperture plane and an amplitude modulating spatiallight modulator situated downstream from the a phase modulating spatiallight modulator at a conjugate of the image plane. However, one skilledin the art readily comprehends that the embodiments disclosed herein maybe deployed in any type of optical illumination system, including butnot limited to: microscopy, optogenetics, 3D printing, lithography and3D displays, just to name a few.

After reading this description it will become apparent to one skilled inthe art how to implement the invention in various alternativeembodiments and alternative applications. However, although variousembodiments of the present invention will be described herein, it isunderstood that these embodiments are presented by way of example only,and not limitation. As such, this detailed description of variousalternative embodiments should not be construed to limit the scope orbreadth of the present invention.

Certain applications of the optical illumination system include, but arenot limited to, multi-site photostimulation, two-photonphotostimulation, structured illumination for microscopy and lightcontrolled 3D fabrication (3D printing), just to name a few.

Regarding multi-site photostimulation, in experimental biology one mayneed to simultaneously create highly focused complex light patterns toinduce photolysis onto caged compounds and optogenetically engineeredcells. The light patterns need to be free of unwanted diffractionpatterns and be able to switch between different patterns rapidly. Thepresently described optical illumination system is ideal for this typeof multi-site photostimulation application.

Regarding two-photon photostimulation, the presently described opticalillumination system overcomes the limitations of conventional DMDsystems for two-photon stimulation. The presently described opticalillumination system is particularly useful for in vivo studies thatrequire a high degree of light penetration into scattering tissue.

Regarding structured illumination for microscopy, the presentlydescribed optical illumination system provides a dynamic means to createcomplex illumination patterns with significantly improved and high lightutilization efficiency. The illumination patterns created by thepresently described optical illumination system advantageously are voidof unwanted diffraction patterns.

Regarding light controlled 3D fabrication, two-photon polymerizationusing SLM controlled holography can be employed to produce microscaledevices because of its flexibility in producing structures with a widerange of geometries. The presently described optical illumination systemimproves the performance of such a fabrication method by masking theunwanted diffraction pattern and by allowing the DMD to independentlycontrol of the light energy that can be delivered to specific locations.Advantageously, although the axial resolution might be limited in suchan embodiment, this can be compensated for by moving the position of theDMD at critical locations. This fabrication method is particularlyuseful for initial substrates that may be in a fluid state and which arenot highly scattering (e.g., clear plastics, tissue scaffolds and thelike).

FIG. 1A illustrates an example optical illumination system 100 accordingto an embodiment. In the illustrated embodiment, the system 100comprises an objective lens 20 having a field of view positioned over animage plane 10 that is perpendicular to the optical axis of theobjective lens. The objective lens 20 comprises a back aperture on anaperture plane 15 that is also perpendicular to the optical axis of theobjective lens. The optical illumination system 100 is configured forepi-illumination and may have a digital camera 25 positioned on theoptical axis of the objective lens 20 via one or more mirrors such asdichroic mirrors 85A and 85B. The system 100 may also include an arclamp 80 to facilitate epi-illumination. The digital camera 25 may becommunicatively coupled (two way) with a computer 30 that has access toa non-transitory computer readable medium such as memory 32. Memory 32is configured to store computer/processor/controller implementableinstructions and executable modules as well as data and temporal spatialpatterns that can be used by the computer 30 and/or the one or morecontrollers (35, 50) to configure the various elements of the opticalillumination system 100 and facilitate operation of the opticalillumination system 100.

Computer 30 is configured to send configuration and operationinstructions to one or more controllers such as controllers 35 and 50.Controller 35 is configured to control the operation of amplitudemodulating spatial light modulator 40 (illustrated in this embodiment asa digital micromirror device, DMD 40). Controller 50 is configured tocontrol the operation of phase modulating spatial light modulator 60(illustrated in this embodiment as a phase only spatial light modulator,SLM 60). Computer 30 is also configured to send configuration andoperation instructions to one or more coherence light sources 65(illustrated in this embodiment as laser 65). Such instructions to laser65 can be sent directly or through a controller (not shown).

Advantageously, the SLM 60 is positioned in a conjugate plane 55 of theaperture plane 15. Similarly, the DMD 40 is positioned in a conjugateplane 45 of the image plane 10. In an alternative embodiment, the DMD 40may be positioned adjacent to a conjugate plane 45 of the image plane 10in order to protect the DMD 40 from being damaged by high intensitylight signals.

The laser 65 is optically coupled with the SLM 60, e.g. via a beamexpander 70 that expands the optical signal from the laser 65 tooptimally fill the aperture of the SLM 60 with the optical signal. Thelaser 65 is configured to illuminate at least a portion of the imageplane by directing an optical signal to the SLM 60, which in turndirects the optical signal to the DMD 40, which applies a desired maskpattern to the optical signal and then directs the patterned opticalsignal to the image plane via the objective lens 20. The laser 65 may beoptically coupled with the SLM 60 via one or more lenses (not shown) ormirrors 80A. The SLM 60 may similarly be optically coupled with the DMD40 via one or more lenses 75A or mirrors 80B. The DMD 40 may similarlybe optically coupled with the objective lens 20 via one or more lenses75B and one or more mirrors 85A.

Advantageously, in the illumination optical path, the SLM 60 ispositioned upstream from the DMD 40 and situated in a conjugate apertureplane 55 position in the optical path that is conjugate to the apertureplane 15 of the microscope objective 20. Similarly, the DMD 40 issituated in a conjugate image plane 45 position in the optical path thatis conjugate to the image plane 10 of the microscope objective 20. In analternative embodiment, the DMD 40 is situated adjacent to a conjugateimage plane 45 position in the optical path that is specifically notconjugate to the image plane 10 of the microscope objective 20. Such aposition may advantageously protect the DMD 40 from high intensity lightand/or mitigate photodamage to the micromirrors during two-photoapplications.

In various embodiments, one or more of the lenses 75A and 75B areemployed to project the pattern from the DMD 40 to fill the backaperture of the objective lens 20. In some embodiments, the angle ofincidence for the SLM 60 is less than or equal to 10 degrees and theangle of incidence for the DMD 40 is substantially equal to 12 degrees.

Certain benefits of the presently descried optical illumination systeminclude: (1) the SLM 60 can direct the light from the laser to theappropriate micromirrors on the DMD 40 to increase the efficiency oflight utilization by the DMD 40; (2) the DMD 40 can impose a pattern onthe optical signal to block unwanted light that is generated by thehologram from the SLM 60 (e.g., zero and higher order diffractionpatterns as well as ghost patterns). The DMD 40 can also be used torapidly switch between a number of different masking patterns, whichallows for simple but very rapid illumination and/or mask patterns.Additionally, the DMD 40 can be used to control the light intensity at aparticular location on the image plane independent of the holographicpattern.

FIG. 1B is a simplified illustration of an optical path in the opticalillumination system 100 of FIG. 1A. In the illustrated embodiment, theoptical path comprises the laser 65 which originates an illuminationoptical signal. The laser 65 may be any of a variety of types of laser,including but not limited to, a continuous wave laser, a pulsed laser,or an amplified laser, just to name a few. The laser 65 directs theoptical signal to the SLM 60 and the SLM 60 in turn directs the opticalsignal to the DMD 40 via one or more lenses 75A. The DMD 40 in turndirects the optical signal to the objective 20 via one or more lenses75B.

FIG. 1C illustrates a plural optical path example of the opticalillumination system 100 of FIG. 1A. In the illustrated embodiment, theplural optical path comprises a plurality of lasers 65 that eachoriginate an illumination optical signal, for example, each laser 65 mayoriginate an optical signal of a different color. Each laser 65 directsits respective optical signal to one of a plurality of SLMs 60 alongseparate optical paths and each SLM 60 in turn directs its respectiveoptical signal to one of a plurality of DMDs 40 via one or more lenses75A. Each of the plurality of DMDs 40 in turn directs its respectiveoptical signal to the objective 20 via a single lens 75B. As shown inthe figure, each optical signal in the plural optical path is mergedinto a single optical path prior to the single lens 75B.

FIG. 2A is a simplified illustration of an alternative optical path inthe optical illumination system 100 of FIG. 1A. The alternative opticalpath is similar to the optical path previously described with respect toFIG. 1B and therefore only the differences will be described. As such,the laser 65 directs the optical signal to the SLM 60 and the SLM 60 inturn directs the optical signal to the DMD 40 via one or more lenses75A. The DMD 40 in turn directs the optical signal to the objective 20via one or more lenses 75C and 75B. In one embodiment, the lens 75C isan optical relay lens that allows additional elements to be incorporatedinto the optical illumination system 100 and also allows the opticalillumination system 100 to be integrated with a microscope system (notshown) without significant modifications to the microscope system.

FIG. 2B illustrates an alternative plural optical path example of theoptical illumination system of FIG. 1A. The alternative plural opticalpath is similar to the plural optical path previously described withrespect to FIG. 1C and therefore only the differences will be described.Each laser 65 directs its respective optical signal to one of aplurality of SLMs 60 along separate optical paths and each SLM 60 inturn directs its respective optical signal to one of a plurality of DMDs40 via one or more lenses 75A. Each of the plurality of DMDs 40 in turndirects its respective optical signal toward the objective lens 20 alongseparate optical paths and through separate single lenses 75C, afterwhich the separate optical paths are merged into a single optical pathand continue to the objective lens 20 via a single lens 75B.

FIG. 3A is a simplified illustration of an alternative optical path inthe optical illumination system 100 of FIG. 1A. The alternative opticalpath is similar to the optical path previously described with respect toFIG. 1B and therefore only the differences will be described. As such,the laser 65 directs the optical signal to the SLM 60 and the SLM 60 inturn directs the optical signal to the DMD 40 via at least two lenses75A and 75D. The DMD 40 in turn directs the optical signal to theobjective 20 via one or lens 75B. In one embodiment, the phase filter 90employs generalized phase contrast to pattern the optical signal ontothe DMA 40.

FIG. 3B illustrates an alternative plural optical path example of theoptical illumination system of FIG. 1A. The alternative plural opticalpath is similar to the plural optical path previously described withrespect to FIG. 1C and therefore only the differences will be described.Each laser 65 directs its respective optical signal to one of aplurality of SLMs 60 along separate optical paths and each SLM 60 inturn directs its respective optical signal to one of a plurality of DMDs40. Between the SLM 60 and the DMD 40, each optical signal on a separateoptical path passes through the first lens 75A and then passes through aphase filter 90 and finally passes through the second lens 75D beforearriving at the DMD 40. Each of the plurality of DMDs 40 in turn directsits respective optical signal toward the objective lens 20 and theseparate optical paths are merged into a single optical path andcontinue to the objective lens 20 via a single lens 75B.

FIG. 4 illustrates a portion of an alternative example opticalillumination system 100 according to an embodiment. The alternativeexample optical illumination system 100 is similar to the opticalillumination system 100 previously described with respect to FIG. 1A andtherefore only the differences will be described. In the illustratedembodiment, the SLM 60 directs the optical signal to the DMD 40, whichapplies a desired mask pattern to the optical signal and then directsthe patterned optical signal toward the image plane via one or morelenses 75A and 75B and the temporal focusing (“TF”) grating 95. The TFgrating 95 compresses the laser pulse to achieve temporal focusing andthen directs the optical signal to the image plane via one or morelenses 75C and the objective lens 20.

Advantageously, the optical illumination system 100 can be used for bothsingle and two-photon illumination. To achieve higher axial resolutionwith two-photon illumination, the TF grating 95 can be added as anadditional stage in the optical path. Temporal focusing can beimplemented by positioning the TF grating 95 in a conjugate plane 45A ofthe image plane 10. In the illustrated embodiment, lenses 75A and 75Btogether project the pattern from the DMD onto the diffraction grating.Lens 75C subsequently projects the pattern onto the image plane 10.

FIG. 5 is a flow diagram illustrating an example process forilluminating a sample in an optical illumination system according to anembodiment. The illustrated process can be carried out by an opticalillumination system such as previously described with respect to FIGS.1-4. Initially, in step 300 the system determines a three dimensionalstructure of the target to be illuminated. Next, in step 310 the systemdetermines an optical illumination pattern to be applied. In step 320the determined illumination pattern is fourier transformed and the DMDis configured in step 330 to apply the appropriate mask to the opticalsignal. Finally, in step 340 the coherence light source (e.g., laser) isconfigured to deliver the illumination pattern in accordance with theappropriate timing.

In an example embodiment of fluorescent microscopy, the fluorescentimage is acquired by the digital camera. The computer receives input(e.g., from a user) and determines the locations on the sample in theimage plane that need to be illuminated. The computer calculates thephase pattern and configures the SLM (e.g., via the previously describedcontroller 50). The computer also determines the locations at the imageplane that need to be masked in order to eliminate any undesired portionof the light pattern. The computer calculates the masking pattern andconfigures the DMD (e.g., via the previously described controller 35).The computer then controls the timing of the laser (directly or via acontroller) to cause the image plane to be illuminated in the desiredpattern.

In an example embodiment of three dimensional printing, the tandem SLMand DMD system is very useful for printing three dimensional structuresthat are otherwise difficult to fabricate by conventional approachesincluding sequential stacking of thin two dimensional layers. A drawbackof the conventional sequential stacking of thin two dimensional layersapproach is the poor structural stability of very thin lattice worksthat are built up as layers. An advantage of using the tandem SLM andDMD system over the conventional approaches is the superior stability ofthese same very thin lattice works if fabricated simultaneously in threedimensions using the tandem SLM and DMD system.

Furthermore, direct laser writing (“DLW”), often involving femtosecondlasers capable of generating a more precisely located multi-photoneffect have been used in 3D lithographic polymerization. This resultsfrom laser induced photo-crosslinking of photo- or thermo-polymerswithin precisely localized spots of micrometer and sub micrometer scale.The approach has proven to be an efficient way to produce usefulmicro/nano-structures with diverse applications. For example, structureswith micro-optics and photonics applications can be made of hard,optically diffracting material, with low shrinkage and distortion duringlithography. An example includes but is not limited to thezirconium-silicon based hybrid sol-gel photopolymer.

Other structures useful in tissue engineering and regenerative medicinecan be made using soft, water soluble photo-polymerizable mixtures thatcan generate three dimensional structures with hydrogel properties. Forexample 3D porous scaffolds have are desirable because they promoteregeneration of tissue by allowing for greater cell-cell contact andbetter exchange of nutrients and wastes and more efficient blood vesselin growth. One application of such a scaffold could be the creation ofartificial skin for treating burns and large skin sores.

The SLM and DMD tandem system enables efficient parallelization of thethree dimensional printing process by allowing precise delivery ofsufficient two photon energy for driving photo-crosslinking reactions indiscrete spots arranged in three dimensions. The rapid and preciselycontrolled movement of those spots can be programmed to build threedimensional structures faster and with more complex features in ashorter period of time because of the multiplexing afforded by thetandem system. Use of the SLM and DMD tandem system also allows formasking of unwanted diffraction patterns as previously discussed.

In one embodiment, the SLM and DMD tandem system directs an opticalsignal to the image plane that comprises a three dimensional pattern oflaser light intensity, where the pattern is shaped by the amplitudemodulating spatial light modulator. Advantageously, the threedimensional pattern of laser light intensity can be designed to triggerphoto-crosslinking of materials to lithographically produce a structureof a predetermined three dimensional pattern where the structurecomprises the photo-crosslinked material. In one embodiment, thephoto-crosslinked material is a rigid material, for example (but notlimited to) a zincromium-silicon material such as Ormisil. Thephoto-crosslinked material can be selected based on desirable opticalproperties for specific uses such as in micro-optic or photonic devicesused in industries such as (but not limited to) the telecommunicationindustry.

In an alternative embodiment, the photo-crosslinked material comprises abiocompatible and porous hydrogel and may, for example, produce anextracellular matrix that can be used to promote three dimensionalassembly of tissue-like material such as (but not limited to) artificialskin.

FIG. 6 is a block diagram illustrating an example wired or wirelessprocessor enabled device (“system 550”) that may be used in connectionwith various embodiments described herein. For example the system 550may be used as or in conjunction with an optical illumination system aspreviously described with respect to FIGS. 1-4. For example, the system550 may operate at least in part as the digital camera, computer,controller or laser as previously described with respect to FIGS. 1-4.The system 550 can be a conventional personal computer, computer server,personal digital assistant, smart phone, tablet computer, or any otherprocessor enabled device that is capable of wired or wireless datacommunication. Other computer systems and/or architectures may be alsoused, as will be clear to those skilled in the art.

The system 550 preferably includes one or more processors, such asprocessor 560. Additional processors may be provided, such as anauxiliary processor to manage input/output, an auxiliary processor toperform floating point mathematical operations, a special-purposemicroprocessor having an architecture suitable for fast execution ofsignal processing algorithms (e.g., digital signal processor), a slaveprocessor subordinate to the main processing system (e.g., back-endprocessor), an additional microprocessor or controller for dual ormultiple processor systems, or a coprocessor. Such auxiliary processorsmay be discrete processors or may be integrated with the processor 560.

The processor 560 is preferably connected to a communication bus 555.The communication bus 555 may include a data channel for facilitatinginformation transfer between storage and other peripheral components ofthe system 550. The communication bus 555 further may provide a set ofsignals used for communication with the processor 560, including a databus, address bus, and control bus (not shown). The communication bus 555may comprise any standard or non-standard bus architecture such as, forexample, bus architectures compliant with industry standard architecture(“ISA”), extended industry standard architecture (“EISA”), Micro ChannelArchitecture (“MCA”), peripheral component interconnect (“PCI”) localbus, or standards promulgated by the Institute of Electrical andElectronics Engineers (“IEEE”) including IEEE 488 general-purposeinterface bus (“GPIB”), IEEE 696/S-100, and the like.

System 550 preferably includes a main memory 565 and may also include asecondary memory 570. The main memory 565 provides storage ofinstructions and data for programs executing on the processor 560. Themain memory 565 is typically semiconductor-based memory such as dynamicrandom access memory (“DRAM”) and/or static random access memory(“SRAM”). Other semiconductor-based memory types include, for example,synchronous dynamic random access memory (“SDRAM”), Rambus dynamicrandom access memory (“RDRAM”), ferroelectric random access memory(“FRAM”), and the like, including read only memory (“ROM”).

The secondary memory 570 may optionally include a internal memory 575and/or a removable medium 580, for example a floppy disk drive, amagnetic tape drive, a compact disc (“CD”) drive, a digital versatiledisc (“DVD”) drive, etc. The removable medium 580 is read from and/orwritten to in a well-known manner. Removable storage medium 580 may be,for example, a floppy disk, magnetic tape, CD, DVD, SD card, etc.

The removable storage medium 580 is a non-transitory computer readablemedium having stored thereon computer executable code (i.e., software)and/or data. The computer software or data stored on the removablestorage medium 580 is read into the system 550 for execution by theprocessor 560.

In alternative embodiments, secondary memory 570 may include othersimilar means for allowing computer programs or other data orinstructions to be loaded into the system 550. Such means may include,for example, an external storage medium 595 and an interface 570.Examples of external storage medium 595 may include an external harddisk drive or an external optical drive, or and external magneto-opticaldrive.

Other examples of secondary memory 570 may include semiconductor-basedmemory such as programmable read-only memory (“PROM”), erasableprogrammable read-only memory (“EPROM”), electrically erasable read-onlymemory (“EEPROM”), or flash memory (block oriented memory similar toEEPROM). Also included are any other removable storage media 580 andcommunication interface 590, which allow software and data to betransferred from an external medium 595 to the system 550.

System 550 may also include an input/output (“I/O”) interface 585. TheI/O interface 585 facilitates input from and output to external devices.For example the I/O interface 585 may receive input from a keyboard ormouse and may provide output to a display. The I/O interface 585 iscapable of facilitating input from and output to various alternativetypes of human interface and machine interface devices alike.

System 550 may also include a communication interface 590. Thecommunication interface 590 allows software and data to be transferredbetween system 550 and external devices (e.g. printers), networks, orinformation sources. For example, computer software or executable codemay be transferred to system 550 from a network server via communicationinterface 590. Examples of communication interface 590 include a modem,a network interface card (“NIC”), a wireless data card, a communicationsport, a PCMCIA slot and card, an infrared interface, and an IEEE 1394fire-wire, just to name a few.

Communication interface 590 preferably implements industry promulgatedprotocol standards, such as Ethernet IEEE 802 standards, Fiber Channel,digital subscriber line (“DSL”), asynchronous digital subscriber line(“ADSL”), frame relay, asynchronous transfer mode (“ATM”), integrateddigital services network (“ISDN”), personal communications services(“PCS”), transmission control protocol/Internet protocol (“TCP/IP”),serial line Internet protocol/point to point protocol (“SLIP/PPP”), andso on, but may also implement customized or non-standard interfaceprotocols as well.

Software and data transferred via communication interface 590 aregenerally in the form of electrical communication signals 605. Thesesignals 605 are preferably provided to communication interface 590 via acommunication channel 600. In one embodiment, the communication channel600 may be a wired or wireless network, or any variety of othercommunication links. Communication channel 600 carries signals 605 andcan be implemented using a variety of wired or wireless communicationmeans including wire or cable, fiber optics, conventional phone line,cellular phone link, wireless data communication link, radio frequency(“RF”) link, or infrared link, just to name a few.

Computer executable code (i.e., computer programs or software) is storedin the main memory 565 and/or the secondary memory 570. Computerprograms can also be received via communication interface 590 and storedin the main memory 565 and/or the secondary memory 570. Such computerprograms, when executed, enable the system 550 to perform the variousfunctions of the present invention as previously described.

In this description, the term “computer readable medium” is used torefer to any non-transitory computer readable storage media used toprovide computer executable code (e.g., software and computer programs)to the system 550. Examples of these media include main memory 565,secondary memory 570 (including internal memory 575, removable medium580, and external storage medium 595), and any peripheral devicecommunicatively coupled with communication interface 590 (including anetwork information server or other network device). Thesenon-transitory computer readable mediums are means for providingexecutable code, programming instructions, and software to the system550.

In an embodiment that is implemented using software, the software may bestored on a computer readable medium and loaded into the system 550 byway of removable medium 580, I/O interface 585, or communicationinterface 590. In such an embodiment, the software is loaded into thesystem 550 in the form of electrical communication signals 605. Thesoftware, when executed by the processor 560, preferably causes theprocessor 560 to perform the inventive features and functions previouslydescribed herein.

The system 550 also includes optional wireless communication componentsthat facilitate wireless communication over a voice and over a datanetwork. The wireless communication components comprise an antennasystem 610, a radio system 615 and a baseband system 620. In the system550, radio frequency (“RF”) signals are transmitted and received overthe air by the antenna system 610 under the management of the radiosystem 615.

In one embodiment, the antenna system 610 may comprise one or moreantennae and one or more multiplexors (not shown) that perform aswitching function to provide the antenna system 610 with transmit andreceive signal paths. In the receive path, received RF signals can becoupled from a multiplexor to a low noise amplifier (not shown) thatamplifies the received RF signal and sends the amplified signal to theradio system 615.

In alternative embodiments, the radio system 615 may comprise one ormore radios that are configured to communicate over various frequencies.In one embodiment, the radio system 615 may combine a demodulator (notshown) and modulator (not shown) in one integrated circuit (“IC”). Thedemodulator and modulator can also be separate components. In theincoming path, the demodulator strips away the RF carrier signal leavinga baseband receive audio signal, which is sent from the radio system 615to the baseband system 620.

If the received signal contains audio information, then baseband system620 decodes the signal and converts it to an analog signal. Then thesignal is amplified and sent to a speaker. The baseband system 620 alsoreceives analog audio signals from a microphone. These analog audiosignals are converted to digital signals and encoded by the basebandsystem 620. The baseband system 620 also codes the digital signals fortransmission and generates a baseband transmit audio signal that isrouted to the modulator portion of the radio system 615. The modulatormixes the baseband transmit audio signal with an RF carrier signalgenerating an RF transmit signal that is routed to the antenna systemand may pass through a power amplifier (not shown). The power amplifieramplifies the RF transmit signal and routes it to the antenna system 610where the signal is switched to the antenna port for transmission.

The baseband system 620 is also communicatively coupled with theprocessor 560. The central processing unit 560 has access to datastorage areas 565 and 570. The central processing unit 560 is preferablyconfigured to execute instructions (i.e., computer programs or software)that can be stored in the memory 565 or the secondary memory 570.Computer programs can also be received from the baseband processor 610and stored in the data storage area 565 or in secondary memory 570, orexecuted upon receipt. Such computer programs, when executed, enable thesystem 550 to perform the various functions of the present invention aspreviously described. For example, data storage areas 565 may includevarious software modules (not shown) that are executable by processor560.

Various embodiments may also be implemented primarily in hardware using,for example, components such as application specific integrated circuits(“ASICs”), or field programmable gate arrays (“FPGAs”). Implementationof a hardware state machine capable of performing the functionsdescribed herein will also be apparent to those skilled in the relevantart. Various embodiments may also be implemented using a combination ofboth hardware and software.

Furthermore, those of skill in the art will appreciate that the variousillustrative logical blocks, modules, circuits, and method stepsdescribed in connection with the above described figures and theembodiments disclosed herein can often be implemented as electronichardware, computer software, or combinations of both. To clearlyillustrate this interchangeability of hardware and software, variousillustrative components, blocks, modules, circuits, and steps have beendescribed above generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled persons can implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the invention. In addition, the grouping of functions within amodule, block, circuit or step is for ease of description. Specificfunctions or steps can be moved from one module, block or circuit toanother without departing from the invention.

Moreover, the various illustrative logical blocks, modules, and methodsdescribed in connection with the embodiments disclosed herein can beimplemented or performed with a general purpose processor, a digitalsignal processor (“DSP”), an ASIC, FPGA or other programmable logicdevice, discrete gate or transistor logic, discrete hardware components,or any combination thereof designed to perform the functions describedherein. A general-purpose processor can be a microprocessor, but in thealternative, the processor can be any processor, controller,microcontroller, or state machine. A processor can also be implementedas a combination of computing devices, for example, a combination of aDSP and a microprocessor, a plurality of microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration.

Additionally, the steps of a method or algorithm described in connectionwith the embodiments disclosed herein can be embodied directly inhardware, in a software module executed by a processor, or in acombination of the two. A software module can reside in RAM memory,flash memory, ROM memory, EPROM memory, EEPROM memory, registers, harddisk, a removable disk, a CD-ROM, or any other form of storage mediumincluding a network storage medium. An exemplary storage medium can becoupled to the processor such the processor can read information from,and write information to, the storage medium. In the alternative, thestorage medium can be integral to the processor. The processor and thestorage medium can also reside in an ASIC.

The above description of the disclosed embodiments is provided to enableany person skilled in the art to make or use the invention. Variousmodifications to these embodiments will be readily apparent to thoseskilled in the art, and the generic principles described herein can beapplied to other embodiments without departing from the spirit or scopeof the invention. Thus, it is to be understood that the description anddrawings presented herein represent a presently preferred embodiment ofthe invention and are therefore representative of the subject matterwhich is broadly contemplated by the present invention. It is furtherunderstood that the scope of the present invention fully encompassesother embodiments that may become obvious to those skilled in the artand that the scope of the present invention is accordingly not limited.

What is claimed is:
 1. An optical illumination system having an opticalaxis comprising: an image plane perpendicular to an optical axis; anamplitude modulating spatial light modulator positioned in a conjugateplane of the image plane and configured to direct an optical signal tothe image plane; an aperture plane perpendicular to the optical axis; aphase modulating spatial light modulator positioned in a conjugate planeof the aperture plane and configured to direct an optical signal to theamplitude modulating spatial light modulator; a coherence light sourceoptically coupled with the phase modulating spatial light modulator,wherein said coherence light source is configured to illuminate at leasta portion of the image plane by directing an optical signal to the phasemodulating spatial light modulator, which directs said optical signal tothe amplitude modulating spatial light modulator, which directs saidoptical signal to the image plane.
 2. The system of claim 1, wherein thecoherence light source comprises a continuous wave laser.
 3. The systemof claim 1, wherein the coherence light source comprises a pulsed laser.4. The system of claim 1, wherein the coherence light source comprisesan amplified laser.
 5. The system of claim 1, further comprising a beamexpander positioned in an optical path between the coherence lightsource and the phase modulating spatial light modulator, said beamexpander configured to direct the optical signal to fill at least aportion of a surface of the phase modulating spatial light modulator. 6.The system of claim 5, wherein said beam expander is further configuredto direct the optical signal to fill substantially all of the surface ofthe phase modulating spatial light modulator.
 7. The system of claim 1,wherein the amplitude modulating spatial light modulator comprises adigital micromirror device.
 8. The system of claim 1, wherein the phasemodulating spatial light modulator comprises a phase only spatial lightmodulator.
 9. The system of claim 1, wherein the angle of incidence ofthe optical signal to the amplitude modulating spatial light modulatoris substantially 12 degrees.
 10. The system of claim 1, wherein theangle of incidence of the optical signal to the phase modulating spatiallight modulator is less than or equal to 10 degrees.
 11. The system ofclaim 1, further comprising a first lens positioned in an optical pathbetween the amplitude modulating spatial light modulator and anobjective lens having a back aperture, wherein the first lens isconfigured to substantially fill the back aperture of the objective lenswith the optical signal.
 12. The system of claim 11, wherein the firstlens is positioned in the optical path equidistant between the amplitudemodulating spatial light modulator and the back aperture of theobjective lens.
 13. The system of claim 12, wherein a first distancebetween the first lens and the amplitude modulating spatial lightmodulator and a second distance between the first lens and the backaperture of the objective lens are each equal to the focal length of thefirst lens.
 14. The system of claim 1, further comprising a second lenspositioned in an optical path between the phase modulating spatial lightmodulator and the amplitude modulating spatial light modulator, whereinthe second lens is configured to position the phase modulating spatiallight modulator in a conjugate plane of the aperture plane.
 15. Thesystem of claim 14, wherein the second lens is positioned in the opticalpath equidistant between the phase modulating spatial light modulatorand the amplitude modulating spatial light modulator.
 16. The system ofclaim 15, wherein a first distance between the second lens and the phasemodulating spatial light modulator and a second distance between thesecond lens and the amplitude modulating spatial light modulator areeach equal to the focal length of the second lens.
 17. The system ofclaim 1, further comprising an optical relay positioned in an opticalpath between the amplitude modulating spatial light modulator and anobjective lens.
 18. The system of claim 1, further comprising a firstlens and a second positioned in an optical path between the phasemodulating spatial light modulator and the amplitude modulating spatiallight modulator and further comprising a phase filter positioned in theoptical path between said first lens and said second lens.
 19. Thesystem of claim 1, further comprising a temporal focusing gratingpositioned in a conjugate plane of the image plane and configured tocompress the optical signal from the amplitude modulating spatial lightmodulator for temporal focusing and direct the temporally focusedoptical signal to the image plane.
 20. The system of claim 1, furthercomprising: a plurality of amplitude modulating spatial light modulatorseach positioned in a conjugate plane of the image plane and configuredto direct an optical signal to the image plane; a plurality of phasemodulating spatial light modulators each positioned in a conjugate planeof the aperture plane and configured to direct an optical signal to arespective one of the amplitude modulating spatial light modulators; aplurality of coherence light sources each optically coupled with arespective one of the phase modulating spatial light modulators, whereinsaid coherence light sources are each configured to illuminate at leasta portion of the image plane by directing an optical signal to arespective one of the phase modulating spatial light modulators, each ofwhich in turn directs said optical signal to a respective one of theamplitude modulating spatial light modulators, each of which in turndirects said optical signal to a merged optical path for delivery to theimage plane.
 21. The system of claim 1, wherein the optical signaldirected to the image plane by the amplitude modulating spatial lightmodulator comprises a three dimensional pattern of laser lightintensity.
 22. The system of claim 21, wherein said three dimensionalpattern of laser light intensity is configured to triggerphoto-crosslinking of materials to lithographically produce a structureof a predetermined three dimensional pattern.
 23. The system of claim22, wherein the photo-crosslinked material comprises azincromium-silicon material.
 24. The system of claim 22, wherein thephoto-crosslinked material comprises a porous hydrogel.
 25. The systemof claim 24, wherein the porous hydrogel comprises an extracellularmatrix.